Re: [PATCH net-next] support SO_PRIORITY cmsg

[kernel test robot <lkp@intel.com>]

Hi Anna,

kernel test robot noticed the following build warnings:

[auto build test WARNING on mkl-can-next/testing]
[also build test WARNING on linus/master v6.12-rc5]
[cannot apply to net-next/main horms-ipvs/master next-20241101]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Anna-Emese-Nyiri/support-SO_PRIORITY-cmsg/20241029-224326
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git testing
patch link:    https://lore.kernel.org/r/20241029144142.31382-1-annaemesenyiri%40gmail.com
patch subject: [PATCH net-next] support SO_PRIORITY cmsg
config: i386-randconfig-141-20241101 (https://download.01.org/0day-ci/archive/20241101/202411012324.a9SOqSqV-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411012324.a9SOqSqV-lkp@intel.com/

smatch warnings:
net/core/sock.c:2870 __sock_cmsg_send() warn: always true condition '(*(cmsg + 12) >= 0) => (0-u32max >= 0)'

vim +2870 net/core/sock.c

  2828	
  2829	int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
  2830			     struct sockcm_cookie *sockc)
  2831	{
  2832		u32 tsflags;
  2833	
  2834		switch (cmsg->cmsg_type) {
  2835		case SO_MARK:
  2836			if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
  2837			    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
  2838				return -EPERM;
  2839			if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
  2840				return -EINVAL;
  2841			sockc->mark = *(u32 *)CMSG_DATA(cmsg);
  2842			break;
  2843		case SO_TIMESTAMPING_OLD:
  2844		case SO_TIMESTAMPING_NEW:
  2845			if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
  2846				return -EINVAL;
  2847	
  2848			tsflags = *(u32 *)CMSG_DATA(cmsg);
  2849			if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
  2850				return -EINVAL;
  2851	
  2852			sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
  2853			sockc->tsflags |= tsflags;
  2854			break;
  2855		case SCM_TXTIME:
  2856			if (!sock_flag(sk, SOCK_TXTIME))
  2857				return -EINVAL;
  2858			if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
  2859				return -EINVAL;
  2860			sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
  2861			break;
  2862		/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
  2863		case SCM_RIGHTS:
  2864		case SCM_CREDENTIALS:
  2865			break;
  2866		case SO_PRIORITY:
  2867			if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
  2868				return -EINVAL;
  2869	
> 2870			if ((*(u32 *)CMSG_DATA(cmsg) >= 0 && *(u32 *)CMSG_DATA(cmsg) <= 6) ||
  2871			    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
  2872			    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
  2873				sockc->priority_cmsg_value = *(u32 *)CMSG_DATA(cmsg);
  2874				sockc->priority_cmsg_set = 1;
  2875				break;
  2876			}
  2877			return -EPERM;
  2878		default:
  2879			return -EINVAL;
  2880		}
  2881		return 0;
  2882	}
  2883	EXPORT_SYMBOL(__sock_cmsg_send);
  2884	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki